Apparatus for spacing and fixing fins on tubes



Sept. 13, 1949.

Filed May 5, 1947 NIH! F. M. BENNETT ET AL APPARATUS FOR SPACING AND FIXING FINS ON TUBES 5 Sheets-Sheet -l Znmentors Frank M Benne w' Carl J Wea ver p 1949. F. M. BENNETT ET AL 2,481,490

APPARATUS FOR SPACING AND FIXING FINS ON TUBES Filed May 5, 1947 s $heets-Sheet 2 3nnent'ors Frank Bemzczi 1 1/ a Carl J: W962 087' a g g L (V, Gttornegs p 1949., F. M. BENNETT ET AL. 2,481,490

APPARATUS FOR SPACING AND FIXING FINS 0N TUBES Filed May 5, 1947 3 Sheets-Sheet 5 Summers Fran/ M Benn ei m' Carl J. Weau cr 0 Fig I dHomegs Patented Sept. 13, 1949 APPARATUS FOR SPACING AND FIXING FINS ON TUBES Frank M. Bennett and Carl J. Weaver, Canton,

Ohio, assignors to Keeprite Corporation,

Youngstown, Ohio, a corporation of Ohio Application May 5, 1947, Serial No. 745,938

7 Claims. 1

The invention relates to apparatus for attaching fins to tubes or pipes for use as heat exchangers in refrigeration apparatus and the like.

In the manufacture of refrigeration apparatus and the like it is common practice to provide coils of tubing or pipes, through which the refrigerant is circulated, with a great multiplicity of closely spaced, sheet metal fins functioning as heat exchangers.

It is necessaray that these fins fit tightly around the tubing or pipes in order that they will be good conductors of heat to or from the tubing. Various methods have been used in the past for attaching the fins to the tubing, some of which are relatively slow and tedious, costly and none of which is entirely satisfactory.

The present invention contemplates the provision of apparatus for rapidly and securely attaching the'fins tightly upon the tubing in such a manner that the cost of this operation is considerably reduced.

Another object is to provide a machine of this character having means for uniformly spacing the fins as they are attached to the tubing.

A further object is to provide such apparatus including means for expanding the tube into a central opening in each fin so as to frictionally hold the fins in fixed position upon the tube.

A still further object is to :provide such apparatus in which a pair of helical grooved rolls separate the fins just prior to the expanding operation.

It is another object of the invention to provide a tube finning machine in which the tube is continuously moved through the machine and over an expanding head which expands the tube so as to fit tightly within the fins.

A further object is to provide apparatus of this type in which the relative speeds of the tube and the helical grooved rolls may be varied in order to vary the spacing of the fins upon the tube.

A still further object is to provide a machine of the character referred to in which a rod or mandrel is anchored at one end and holds in position an expanding head at its other end, the tube being slidably moved over the expanding head by means of a draw bench.

It is also an object of the invention to provide such a machine in which one end of the tube is clamped in a box detachably connected to the chain of the draw bench.

Another object is to provide a machine of this type in which the fins are loosely threaded upon the tube in closely spaced position, each fin having means thereon for preventing close packing together of the fins, whereby as the fins approach the helical grooved spacing rolls they may be automatically manipulated by the rolls.

A further object of the invention is to provide a tube finning machine of the character referred to in which the rod or mandrel supporting the expanding head is located between the helical grooved rolls with the expanding head upon the rod or mandrel located at the point where the fins pass out of the grooved rolls.

A still further object is to provide means upon the machine for initially expanding the leading end of the tube before it is moved through the helical grooved rolls and over the expanding head.

The above objects together with others which will be apparent from the drawings and following description, or which may be later referred to, may be attained by constructing the improved tube finning machine in the manner hereinafter described in detail and illustrated in the accompanying drawings in which;

Figure l is a side elevation of a tube finning machine embodying the invention, showing a tube passing through the machine and fins being fixed thereon;

Fig. 2 a fragmentary, transverse, sectional view through a portion of the driving mechanism of the machine;

Fig. 3 a top plan view of the machine in the position shown in Fig. 1;

Fig. 4 an enlarged, transverse sectional view through the helical grooved rolls, taken on the line 4-4, Fig. 3;

Fig. 5 an enlarged, longitudinal sectional view through the tube showing the expanding head upon the rod or mandrel and the manner in which the same expands the tube into the fins;

Fig. 6 a side elevation of the box detachably connected to the draw bench chain for clamping the leading end of the tube to pull it over the expanding head;

Fig. 7 a fragmentary rear elevation of the draw bench clamping box shown in Fig. 6;

Fig. 8 a front elevation of the tube clamping means within the box;

Fig. 9 a side elevation of the and,

Fig. 10 a transverse section through the box and chain of the draw bench, taken on the line |0|0, Fig. 6.

clamping means;

Referring now more particularly to the embodi-- ment of the invention illustrated in the accompanying drawings, in which like numerals refer to similar parts throughout the several views, the apparatus may include the drive mechanism indicated generally at I5 and located substantially at the center of the machine, the support bench 3 it of considerable length located at one aid thereof, and the draw bench of similar length indicated generally at I! and located at the other side thereof.

The drive mechanism is located beneath the central table I8 which is of uniform height with the support bench I6 and the draw bench l1. Located beneath this central table I8 is the motor [9, or other prime mover whichgmayfurnish power for the machine.

A pulley or sprocket may be fixed upon the motor shaft 2| for conveying the power therefrom, through a belt or chain 22; to the various working parts of the apparatus. The belt 22 may engage the pulley 23 upon a shaft 24, Journailed as at 25 and arranged to drive reduction gearing located in the gear housing 25.

A sprocket 21 may be mounted upon the shaft 24 and connected, as by a chain 28, with a sprocket 29 upon the shaft 30, upon which may be removably mounted a change gear 3| of desired diameter arranged to mesh with a change gear 32 removably mounted upon the parallel shaft 33.

A sprocket 34 may be fixed upon the shaft 33 and connected by a chain 35 with a sprocket 35 upon the shaft 31, upon which is mounted a gear 38 meshing with a gear 39 of equal diameter mounted upon the similar shaft 40.

Sprockets 4| are mounted upon the shafts 31 and 40 and connected by chains 42 with sprockets 43 upon the shafts 44 of the spaced, parallel helical grooved rolls 45, journalled in bearings 48 which may be assembled upon a base plate 41 mounted upon the top of the central table l8 as by the bolts 48 located through slots 49 in the base plate 41 so that the helical roll assembly may be accurately positioned upon the table Ill.

The rolls have oppositely disposed, uniformly spaced, helical grooves 50 formed therein throughout their lengths. A channel guide 5|, outwardly flared at its left end as indicated at .52 in Figs, 1 and 3, may be mounted upon the table l8 and extended over the base plate 41 between the helical grooved rolls 45.

A shaft 53 is driven by the reduction gearing in the housing 28 and a sprocket wheel 54 is mounted thereon for driving the draw bench chain 55 which passes around said sprocket wheel and up over an idler 58 and then forwardly or to the right through a slot 51 extending longitudinally throughout the length of the draw bench N, then over an idler 58 at the far end of the draw bench, and then back to the drive sprocket 54 so as to continuously move the chain 55 forwardly or in the direction of the arrows sho in Figs. 1 and 3.

The draw bench chain is continuously operated at uniform speed and the speed of the helical grooved rolls 45 may be varied relative to the speed of the draw bench chain by placing any desired relatively proportioned gears 3| and 32 upon the shafts 3t and 33.

A hand wheel 58 may be mounted upon the shaft 40 for manually operating the helical grooved rolls 45 when necessary or desirable during the operation of the machine and a switch 8| is provided for controlling the circuit to the motor I 9.

g A bracket 52 may be rigidly mounted upon the the channel guide 59 formed in the longitudinal slot 51 .of the draw bench l1 and to receive a portion of the chain 55.

These flanges 88 are connected at their forward ends by the transverse flange 10 having slot 'Il therein to receive a link of the chain in vertical position as indicated at A in Figs. 6 and 10, while the next rearward, horizontally disposed link B will abut the end flange 10 so as to move the box 51 with the chain 55.

The rear end of the box 61 is provided at its upper edge with the slot 12 to receive the forwardend portion of the tube 84 which is clamped in the clamping device shown in detail in Figs. 8 and 9 and comprising the U-shape frame 13 10- cated in the rear end portion of the box 61 against the rear end wall 14.

A normally stationary, lower clamping jaw 15 is mounted at the bottom of the U-shape frame 13 and the movable, upper clamping jaw 16 is vertically slidably mounted therein and operated by the clamping screw 11 located through the nut I8 at the top of the frame 13 and having a swivel connection with the movable clamping jaw 16 as indicated at 19.

For the purpose of initially expanding the front or leading end portion of the tube 34, in order to start the operation of the machine, a collapsible expanding head may be mounted upon a screw 8| threaded through a stationary nut 82 in the box 51, or any other collapsible expander may be used.

The fins 83, which are to be mounted upon the tube, may be of the form'best shown in Figs. 4 and 5 of the drawings, being formed of sheet metal of rectangular shape preferably with I rounded comers and reinforcing ribs 84 pressed therein.

Apertures may be punched in the corner por-' tions of these fins surrounded by the outturned flanges 85. These flanges are for the purpose of preventing the fins from packing tightly together when they are placed upon the tube 64.

In the operation of the machine, to fix the fins tightly upon the tube, the proper number of the metal fins 83 are placed upon the tube as shown at the left side of Figs. 1 and 3. Shoes 59 may be located over the tube for sliding contact with the table to support the tube as it is moved through the machine. The forward or leading end of the tube may be expanded for a short distance by locking it between the clamping jaws I5 and 18 in the box 81 and operating the screw 8| to insert the expanding head 80 into the end portion of the tube and to then pull the collapsible expander outward to the end of the tube to expand the same.

The expanding head 85 is then removed from the rod or mandrel 53 and the tube 54 is slidably located over the rod 83 after which the expanding head 85 is replaced upon the rod and the expanded forward end of the tube is pulled over the expanding head 85 and clamped between the laws I5 and 15 of the box 61 which has been detachably connected to the chain 55 of the draw bench in the manner above described.

The motor I8 is then started moving the draw bench chain forwardlsnor to the right as viewed in Figs. 1 and 3, and rotating the helical grooved rolls 45 in opposite directions as indicated by the arrows in Figs. 3 and 4, drawing the tube with the fins loosely mounted thereon between the helical grooved rolls 45 and over the expanding head 65.

The side edges of the fins 83 will be received, one at a time, in the helical grooves 50 of the rolls 45 separating the fins and moving them forward, or to the right, and as each fin reaches the point where it leaves the grooves 50 of the rolls 45, the tube will be expanded so as to tightly fit within the flanged, central opening 85 of the fin as best shown in Fig. 5.

The spacing of the fins is uniform as they are fixed upon the tube and this spacing may be varied as desirable or necessary by varying the speed of rotation of the helical grooved rolls 45 relative to the speed of movement of the tube 64 through the machine.

When it is desired to leave a portion of the tube 54 bare, or without fins mounted thereon, in

' order to bend the same into a coil, the rotation' of the helical grooved rolls 45 may be temporarily stopped by operating the clutch 81, shown in Fig. 1 to stop rotation of the shaft 30 which drives the helical grooved rolls through the gearing illustrated in Figs. 1 and 2 and above described. At the proper time the clutch 81 may be again operated to cause rotation of the helical grooved rolls 45 and the operation will be continued as above described.

We claim:

1. Apparatus for fixing fins upon a tube comprising means for supporting a tube with a plurality of perforate fins loosely strung thereon, an expanding head inserted into the tube, a pair of helical grooved rolls adjacent to the expanding head for uniformly spacing the fins upon the tube, means for rotating the rolls, and independent means for moving the tube longitudinally relative to the expanding head and the rolls to expand the tube into each fin as it leaves the rolls so that the fins will fit tightly upon the tube in uniformly spaced position.

2. Apparatus for fixing fins upon a tube comprising means for supporting a tube with a plurality of perforate fins loosely strung thereon, an expanding head inserted into the tube, a pair of helical grooved rolls adjacent to the expanding head for uniformly spacing the fins upon the tube, means for rotating the rolls, and independent means for continuously moving the tube longitudinally relative to the expanding head and the rolls to expand the tube into each fin as it expanding head inserted into the tube, a pair of helical grooved rolls adjacent to the expanding head for uniformly spacing the fins upon the tube, means for rotating the rolls, and independent means for continuously moving the tube longitudinally relative to the expanding head and the rolls to expand the. tube into each fin as it leaves the rolls so that the fins will fit tightly upon the tube in uniformly spaced position, and means for varying the relative speed of the rolls and the tube to vary the spacing of the fins upon the tube.

5. Apparatus for fixing fins upon a tube comprising means for supporting a tube with a plurality of perforate fins loosely strung thereon, an expanding head inserted into the tube,. a pair of helical grooved rolls adjacent to the expanding head for uniformly spacing the fins upon the tube, means for rotating the rolls, and independent means for moving the tube longitudinally relative to the expanding head and the rolls to expand the tube into each fin as it leaves the rolls so that the fins will fit tightly upon the tube in uniformly spaced position, and means for stopping the rolls for a predetermined time to have a predetermined portion of the tube bare of fins.

6. Apparatus for fixing fins upon a tube comprising means for supporting a tube with a plurality of perforate fins loosely strung thereon, an expanding head inserted into the tube, a pair of helical grooved rolls adjacent to the expanding head for uniformly spacing the fins upon the tube, means for rotating the rolls, and independent means for continuously moving the tube longitudinally relative to the expanding head and the rolls to expand the tube into each fin as it leaves the rolls so that the fins will fit tightly upon the tube in uniformly spaced position, and means for stopping the rolls for a predetermined time to have a predetermined portion of the tube here of fins,

- '7. Apparatus for fixing fins upon a tube comprising'meansfor supporting a tube with a pluleaves the rolls so that thefins will fit tightly upon the tube in uniformly spaced position;

3. Apparatus for fixing fins upon a tube com-"j prising means for supporting a tube with a plurality of perforate fins loosely strung thereon. an expanding head inserted into the tube, a pair of helical grooved rolls adjacent to the expanding head for uniformly spacing the fins upon the tube, means for rotating the rolls, and independent means for moving the tube longitudinally relative to the expanding head and the rolls to expand the tube into each fin as it leaves the rolls so that the fins will fit tightly upon the tube in uniformly spaced position, and means for varying the relative speed of the rolls and Eh; tube to vary the spacing of the fins upon the 4. Apparatus for fixing fins upon a tube comprising means for supporting a tube with a plurality of perforate fins loosely strung thereon, an

rality of perforate fins loosely strung thereon, an expanding head inserted into the tube, a pair of helical grooved rolls adjacent to the expanding head for uniformly spacing the fins upon the tube, means for continuously rotating the rolls, and independent means for continuously moving the tube longitudinally relative to the expanding head and the rolls to expand the tube into each fin as it leaves the rolls so that the fins will fit tightly upon the tube in uniformly spaced posiion.

FRANK M. BENNETT. CARL J. WEAVER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

